$30 Million dollar mark

$...dollar? Is that from the Department of Redundancy Department?

and you can put any unit you want after ZERO

From the summary:

the company is very close to the $30M mark

The dollar sign is the unit. The units are dollars. It is common usage to have dollar signs precede the number. What are you complaining about? And why on earth did someone think it was insightful?

I(sic) takes a *tremendous* amount of design work to get an internal combustion engine to "burn clean" using a single fuel; making it a "universal fuel capable" and still "burn clean" will be impossible.

You realize that a Stirling engine is an external combustion engine, right?